Article of footwear with improved structure

[0037]The first embodiment described below relates, for example, to an article of footwear for walking or running on flat or mountainous terrain. However, the first embodiment is applicable to other fields, such as those mentioned above.

[0038]The first embodiment is described below with reference to FIGS. 1 to 10.

[0039]As shown in FIGS. 1 and 2, an article of footwear 1 is provided to receive the foot of the user. For convenience, the article of footwear 1 will be considered as a shoe in the following description although, as will be shown in detail, its structure is completely unusual. Thus, the shoe 1 extends lengthwise along a longitudinal direction L, between a rear end or heel 4 and a front end or tip 5, and widthwise along a transverse direction W, between a lateral side 6 and a medial side 7.

[0040]As shown, the upper of the shoe 1 comprises a lower portion 10, provided to surround the foot, and has no upper portion. Alternatively, however, an upper of a shoe of the invention encompasses one having both a lower portion and an upper portion, the latter being provided to surround the ankle and possibly the lower leg.

[0041]According to the first embodiment described, the shoe 1 extends heightwise from a bottom 12 to a top end 13, that is to say, up to the free end of the lower portion 10 or of the shoe 1. The bottom is a subdivision of the shoe, on which the foot takes support.

[0042]The shoe 1 is structured to allow good foot rolling movement during walking, transmission of sensory information and forces when taking support or jump landing. Therefore, the shoe 1, or article of footwear, is relatively flexible.

[0043]As described in detail below, the shoe 1 comprises a first envelope 21 extending lengthwise along the longitudinal direction L, from a rear end 24 to a front end 25, widthwise along the transverse direction W, between a lateral side 26 and a medial side 27, and heightwise from a bottom 28 to a top end 29. This enables the first envelope to surround and support the foot of the user. For its construction, the first envelope includes yarns linked to one another mechanically, as explained below. Also, at least a portion of the yarns of the first envelope comprises at least one hot-melt filament, as also explained below.

[0044]According to the first embodiment, and in a non-limiting manner, the yarns of the first envelope, comprising at least one hot-melt filament, are distributed over the entire first envelope 21, and the melting of the yarns during manufacture contributes, to a greater or lesser extent, depending on their quantity and concentration, to the strength and/or the adhesion and/or the abrasion resistance of the first envelope. In fact, the melting of the yarns enables the first envelope 21 to retain its shape by itself. This means that it does not collapse if no external force is applied thereto, even if it is not associated with other components. It can be said that the first envelope 21 is a unitary component, on the one hand, and that it can form a self-supporting component, on the other hand, giving shape to the shoe, to a greater or lesser extent, as a function of the quantity/concentration of the yarns. Accordingly, the first envelope 21 provides shape to the shoe 1. In other words, the rear end 24, the front end 25, the lateral side 26 and a medial side 27, the bottom 28 and the top end 29 of the first envelope demarcate the rear end 4, the front end 5, the lateral side 6, the medial side 7, the bottom 12 and the top end 13, respectively, of the article of footwear or shoe 1. The minimalist structure used for the envelope 21 ensures simplicity, lightness, and many other advantages, as explained below.

[0045]Without limitation, and still according to the first embodiment of the invention, the shoe 1 also includes a second envelope 31 extending lengthwise along the longitudinal direction L, from a rear end 34 to a front end 35, widthwise along the transverse direction W, between a lateral side 36 and a medial side 37, and heightwise from a bottom 38 to a top end 39. The second envelope 31 also covers the foot, in the same fashion as the first envelope 21. The second envelope 31 is arranged outside of the first envelope 21 and, thereby, indirectly covers the foot. The final shape of the shoe 1 is provided by both the first envelope 21 and the second envelope 31. The advantage of using two envelopes will be more apparent below.

[0046]Still in the context of the invention, the second envelope 31 comprises yarns linked to one another mechanically, at least a portion of the yarns comprising at least one hot-melt filament, the yarns comprising at least one hot-melt filament being distributed over the entire second envelope 31, and the shape of the second envelope being solidified through melting of the yarns comprising at least one hot-melt filament. Here again, the melting enables the second envelope 31 to maintain its shape by itself. This means that it does not collapse if no external force is applied thereto, even if it is not associated with other components. It can be said that the second envelope 31 is a unitary component, on the one hand, and that it can form a self-supporting component, on the other hand, giving shape to the shoe, to a greater or lesser extent, as a function of the quantity/concentration of the yarns. Consequently, the second envelope 31 also provides shape of the shoe 1. In other words, the rear end 34, the front end 35, the lateral side 36, the medial side 37, the bottom 38, and the top end 39 of the second envelope 31 also demarcate the rear end 4, the front end 5, the lateral side 6, the medial side 7, the bottom 12, and the top end 13, respectively, of the article of footwear or shoe 1. The minimalist structure used for the envelope 31 ensures simplicity, lightness, and many other advantages, as explained below.

[0047]To better highlight the specificities of the invention, it is useful to describe how the envelopes 21, 31 are manufactured. This is done below with reference to FIGS. 3 to 7 in particular.

[0048]As initially shown schematically in FIGS. 3 and 4, each envelope 21, 31 is obtained by manufacturing a sleeve 41, that is to say, a flexible tube made of yarns linked to one another mechanically. Alternatively, it can be said that an envelope 21, 31 is a sock, as explained below with regard to all the drawing figures. The sleeve 41 is a preform for making the article of footwear 1. Without limitation, and in connection with the first embodiment, the sleeve 41 makes it possible to obtain both the first envelope 21 and the second envelope 31. The sleeve 41 extends lengthwise from a first end 42 to a second end 43. The first end 42 is closed using any technique known to one with ordinary skill in the art, such as stitching after folding, adding an end piece made of yarns linked to one another mechanically, or any equivalent. The second end43 is merely an opening.

[0049]The sleeve 41 makes it possible to manufacture the envelopes 21, 31 in one piece. Here, the first envelope 21 and second envelope 31 are coextensive. This simplifies the manufacture by reducing the number of components and the time required for implementation.

[0050]The association of the yarns used to make the sleeve 41, and therefore the envelopes 21, 31, is presented with reference to FIGS. 5 and 6. Generally speaking, the yarns are provided to be associated with one another using any suitable textile technique, such as knitting, weaving, braiding, or the like. In the case of knitting, it is possible to use a single- or double-knit circular knitting machine, a cylinder knitting machine, or a flat knitting machine. Two knitting zones may be joined to one another using the intarsia knitting technique or embroidery. Various decorative patterns can be obtained directly when knitting with the Intarsia method, embroidery, the Jacquard knitting technique, or the like. FIG. 5 shows a conventional weaving with first yarns 44 oriented along a first direction, second yarns 45 oriented along a second direction, the first 44 and second 45 yarns intersecting to form a flexible mesh. FIG. 6 shows knitting with three yarns 45, 47, 48 arranged in interpenetrating loops. However, a number of other arrangements are possible.

[0051]The sleeve 41 is manufactured, for example, with a flat knitting machine, which makes it possible to vary the cross section, that is to say, the diameter of the sleeve, to make shape variations for the heel, to create openings for passage of the laces, to vary the thickness of the wall of the sleeve, or in particular to vary the tightening of the loops. In fact, the flat knitting machine provides a wide range of adjustment possibilities, and it is adapted to make sleeves of all sizes, whether in diameter or in length. As such, the flat knitting is more practical than the circular knitting machine. Indeed, the circular knitting machine works on a reduced range in the area of the sleeve diameter. It is therefore necessary to use a plurality of different circular knitting machines to make a complete line of sleeves 41, that is to say, a complete line of shoes encompassing all shoe sizes, where a single flat knitting machine would be sufficient. In the end, a flat knitting machine makes it possible to make one or more three-dimensional envelopes, with all desired features, and to the desired shoe size.

[0052]A yarn within the context of the invention will next be defined.

[0053]First, the yarn may be a monofilament obtained, for example, by extruding a hot-melt synthetic material, such as polyamide, polyurethane, polyethylene, or any equivalent or similar material. The production of a filament is continuous, in a way comparable to silk filament produced by a spider. The filament may be mono-component or mono-material, in the sense that its transverse cross section is uniform. But the filament may also be multi-component, e.g., bi-component. In this latter case, a transverse cross section of a filament shows a core comprised of a first material, and a peripheral envelope surrounding the core, such envelope being comprised of a second material. Each material may be hot-melt, or only one material may be hot-melt. If both materials are hot-melt, their melting temperatures are different.

[0054]Next, the yarn may be multi-filament. In this case, it is obtained by associating a plurality of filaments. Such an association is schematically shown in FIG. 7. Here, all of the filaments 49 are of the same type, in the sense that each has the same melting point. But combinations of filaments of different types can be provided, some of which may be meltable and others may not, or may have different melting points. The filaments are associated with one another by any known technique.

[0055]Furthermore, the yarn can be obtained in the form of a fiber mesh. Here, a fiber is a filament of limited length. The fibers are associated in tight contact to form the mesh, by any known technique, and especially by twisting. Fibers, especially natural fibers such as cotton, are traditionally kept together by friction. However, for the invention, the fibers are kept together either by friction or a combination of friction and melt-adhesion, or yet entirely by adhesion, because the invention uses hot-melt materials.

[0056]Having generally presented the structure of the sleeve 41, its use for the manufacture of the shoe 1 can now be explained. However, to remain in the context of the first embodiment, it is useful to first explain that the article of footwear 1, or shoe, includes a reinforcement 51. It is shown more clearly below that this reinforcement is associated with the envelopes 21, 31 by nesting at the time of manufacture of the shoe 1, in order to provide the latter with specific capabilities.

[0057]As shown in FIG. 8, the reinforcement 51 is a component extending lengthwise from a rear end 54 to a front end 55, widthwise between a lateral side 56 and a medial side 57, and heightwise from a bottom 58 to a top end 59. The reinforcement 51 has a length and a width similar to the lengths and widths of the envelopes 21, 31. More specifically, the reinforcement 51 extends lengthwise, in relation to the first envelope 21, from the rear end 24 to the front end 25, widthwise between the lateral side 26 and the medial side 27, and heightwise from the bottom 28 to the top end 29. By definition, this makes it possible to reinforce the first envelope 21, and therefore the article of footwear 1, in particular in the area of the bottom 12 and at the periphery of the bottom.

[0058]In a non-limiting fashion, the reinforcement 51 carries a tightening device 61. The tightening device, for example, includes keepers 62 located in the area of the top end 59, as well as a lace 63 and a blocking device 64, known to one with ordinary skill in the art. It is therefore possible to tighten or loosen the reinforcement 51 and, thereby, to tighten or loosen the shoe 1, as will be more apparent below. Other tightening means may be provided.

[0059]According to the invention, as is generally understood with reference to FIGS. 1 to 10, the article of footwear 1 comprises a functional component 71 arranged opposite the first envelope 21, as well as a positioner for positioning the functional component 71 with respect to the envelope. It will be shown below that, according to the first embodiment, the functional component 71 provides the article of footwear 1 with specific localized mechanical properties. The positioner, which is described below, enables the functional component 71 to be positioned precisely on the first envelope 21 and, therefore, ultimately on the article of footwear 1. Given that the article of footwear 1 is a three-dimensional object, the invention enables positioning of the functional component on a volume. In fact, the functional component 71 has a three-dimensional structure. This structure has a shape identical or similar to the surface to which it must conform. This facilitates its positioning and enables it to be positioned at the desired location.

[0060]Given that the article of footwear 1 has concave portions and/or convex portions, the functional component 71, in most cases, also has concave portions and/or convex portions due to its conformability properties, conferred by the deformation of its mechanical structure (meshes) and/or the use of elastane filaments and/or elastic filaments.

[0061]In the specific case of the first embodiment of the invention, the functional component 71 is made from a tubular section, that is to say, a sleeve portion or sock portion. This makes it possible to arrange it at the desired location opposite the envelopes 21, 31 by slipping it onto one of the two, or on both at the same time. The sock may be devoid of a heel, or may comprise one or more heels, and the sock may be closed at one or both ends. When the functional component is in the form of a sock or an ankle sock, it makes it possible to further obtain a very precise longitudinal positioning on the envelope 21, 31, due to the stops formed by the heel and front end of the ankle sock.

[0062]For example, in a non-limiting manner, the functional component 71 is arranged on the first envelope 21. In order to understand its role, it should be noted that the article 1 has four successive zones, from the rear end 4 to the front end 5. These zones include a heel zone 72, an arch of the foot zone 73, a metatarsal zone 74, and a front zone for receiving the toes. For the first embodiment of the invention, the functional component is located in the metatarsal zone. In fact, the functional component completely bypasses the metatarsal zone, by being oriented in a transverse plane of the article of footwear 1. This provides the latter with greater resistance to transverse deformations. A resulting advantage is better support on the ground in the area of the metatarsus, with greater transverse stability.

[0063]Still in a non-limiting fashion, as will be more apparent below, the functional component 71 is housed between the first envelope 21 and the second envelope 31. This facilitates its integration into the article 1.

[0064]As is the case for the envelopes 21, 31, the functional component 71 comprises yarns 44 to 48 linked to one another mechanically, at least a portion of the yarns comprising at least one hot-melt filament 49. This makes it possible to provide at least one subdivision of the functional component 71, with a stable self-supporting structure once melting has been carried out.

[0065]Here, the yarns comprising at least one hot-melt filament are distributed over the entire functional component 71, and the shape of the functional component 71 may or may not be solidified by the melting of the yarns comprising at least one hot-melt filament.

[0066]In a non-limiting fashion, and still according to the first embodiment of the invention, the positioner for positioning the functional component 71 in relation to the first envelope 21 comprises reversibly extensible yarns, in addition to the tubular shape of the sleeve portion, the yarns being associated with the structure of the functional component. This means that a portion of the yarns forming the functional component are elastic. These yarns are made of elastane, for example. In practice, the functional component 71, that is to say, the sleeve portion, due to its tubular shape and the presence of extensible yarns, is slipped onto and positioned at the desired location around the first envelope 21, as will be understood below.

[0067]Next explained is the use of the sleeve 41 for the manufacture of the shoe 1, according to FIGS. 9 and 10. In fact, the components of the shoe 1 are assembled by hand, without a complex and expensive machine, as was the case for the prior art.

[0068]It can be understood from FIGS. 9 and 10 that the sleeve 41 is fitted onto a component 76 referred to as a last, shaped to emulate the foot of a user. The sleeve is applied to the last 76 in the manner of a sock on a foot. The sleeve 41 conforms to the shape of the last 76 due to its elasticity, which is inherent in its textile structure. The elasticity that enables shaping of the sleeve 41 is due to a reversible elastic deformation of the constituent meshes of the sleeve. Then, the functional component 71, in this case the sleeve portion, is slipped onto the last 76 around the first envelope 21 at the desired location, in this case in the metatarsal zone 74. The elasticity holds it in the desired position, because it exerts restraint on the last and on the first envelope. Then, the reinforcement 51 is nested on the subdivision of the sleeve 41 which becomes the first envelope 21. Then, the subdivision of the sleeve 41 that becomes the second envelope 31 is folded over the reinforcement 51, thereby covering the latter and the subdivision assigned to the first envelope and the functional component 71. This is sufficient to form the subassembly of the shoe 1 that envelopes the foot, a subassembly that ultimately includes the first envelope 21, the functional component 71, the reinforcement 51, and the second envelope 31. The second envelope 31 has an opening 77 for passage of the lace 63. It then suffices to subject the subassembly to a higher temperature, using any suitable technique, to melt the hot-melt filaments of the envelopes and of the functional component 71 only as appropriate, and thus provide the shoe 1 with its geometry, among other things. In the present case, the functional component 71 improves the assembly resistance to deformation, in the manner of a torsion box, which is particularly important in the metatarsal zone to give more stability to the assembly. After heating, the last 76 may be removed from the subassembly. The shoe 1 is then almost finished. It suffices, according to the first embodiment, to add an outer sole assembly 78 thereto. As shown in FIGS. 1 and 2, the article of footwear 1, or shoe, comprises an outer sole assembly 78. This outer sole assembly is adapted to take support on the ground and, therefore, is structured to resist wear by friction and also to dampen impacts. It thus includes a wear layer 79 and a damping layer 80, for example. FIG. 2, which is a transverse cross section in the region of the shoe configured to receive the arch of the foot, shows that the bottom 12 has a non-planar geometry, substantially identical to that of the aforementioned arch. The shoe 1 according to the invention is indeed capable, as has been mentioned, of conforming to the shape of the foot. It is thus not necessary to add an inner sole to the shoe 1 to reproduce the arch of the foot, or the other aspects of the bottom of the foot. This thus simplifies the shoe 1 according to the invention, compared to a prior art shoe. This also lightens the shoe 1 and thereby reduces the mechanical inertias. A resulting advantage is improved athletic performance. The shoe according to the invention is well suited, for example, to a long-distance runner.

[0069]FIG. 2 also shows that the reinforcement 51 is located between the first envelope 21 and the second envelope 31. As a corollary, the tightening device 61 is also mainly located between the first envelope 21 and the second envelope 31. This preserves the tightening device, for example by preventing the lace 63 from catching branches during a race in the forest.

[0070]Still with reference to FIG. 2, but also to FIG. 1, the first envelope 21 and second envelope 31 are shown to be continuous along a transverse cross section. These envelopes therefore extend continuously in the area of their respective upper ends 29, 39, and thus in the area of the top end 13 of the shoe.

[0071]As understood from FIG. 1, but also from FIG. 3 or 4, the boundary between the first envelope 21 and the second envelope 31 is a fold 83 demarcating a foot insertion opening 84. The periphery the foot insertion opening 84 is therefore demarcated simply by folding the two envelopes 21, 31 on one another. This means that this periphery does not have a stitch or an attached element, as in the prior art and, therefore, that the shoe 1 does not cause discomfort to the user, including in the area of the opening 84.

[0072]By way of example, as seen in FIG. 3, or in FIG. 4, the first envelope 21 has three zones 91, 92, 93 having different mechanical properties. These properties are dependent upon the percentage of hot-melt filaments contained in the yarns. Without limitation, a first zone 91 with a high concentration of hot-melt filaments, for example between 60 and 100%, is provided here. The first zone 91 demarcates the bottom 28 and the periphery of the bottom. A second or intermediate zone 92 with an average concentration of hot-melt filaments, for example between 30 and 70%, is then provided. The second zone extends mainly in the area of the lateral 26 and medial 27 sides. A third zone 93 with a low concentration of hot-melt filaments, for example between 5 and 40%, is finally provided. The third zone extends mainly in the area of the top end 29. This arrangement renders the first envelope 21 relatively inflexible towards the bottom 28, but progressively flexible towards the top end 29. The flexibility, or elasticity, is conditioned by the type of knitting stitch loops and/or by the elasticity of the constituent material of the stitch loops. This elasticity enables the first envelope 21 to remain in contact with the foot, the ankle or the lower leg, and thereby prevents the intrusion of foreign bodies. An elastic yarn kept tensioned provides good foot support.

[0073]Similarly, the second envelope 31 has three zones 101, 102, 103 having different mechanical properties. These properties again are dependent upon the percentage of hot-melt filaments contained in the yarns. Without limitation, a first zone 101 with a high concentration of hot-melt filaments, for example between 60 and 100%, is provided here. The first zone 101 demarcates the bottom 38 and the periphery of the bottom. An intermediate or second zone 102 with an average concentration of hot-melt filaments, for example between 30 and 70%, is then provided. The second zone extends mainly in the area of the lateral 36 and medial 37 sides. A third zone 103 with a low concentration of hot-melt filaments, for example between 5 and 40%, is finally provided. The third zone extends mainly in the area of the top end 39. This arrangement renders the second envelope 31 relatively inflexible towards the bottom 38, but progressively flexible towards the top end 39. Here again, the flexibility towards the top end enables the second envelope 31 to remain pressed onto the foot, the ankle or the lower leg, and thereby prevents the intrusion of foreign bodies. Again, an envelope comprising an elastic yarn kept tensioned provides good foot support.

[0074]For each envelope 21, 31, the melting of filaments determines the physical or mechanical properties in proportion to the hot-melt filaments. For example, the greater their number is, in percentage, the higher the resistance to abrasion. Conversely, if the percentage of hot-melt filaments is reduced, the elasticity is maintained. In other words, the higher the percentage of hot-melt filaments, the higher the resistance to abrasion and, by corollary, the elasticity is reduced. Conversely, if the percentage of hot-melt filaments is low, then the resistance to abrasion is low and, by corollary, the elasticity is significant.

[0075]Ultimately, when the envelopes 21, 31 and the functional component 71 are assembled, the flexibility of the shoe 1 increases vertically from the bottom 12 to the top end 13. This enables the shoe to support the foot, on the one hand, and to reversibly widen in the area of the top end 13 in order to make it easier to put on or remove the shoe, on the other hand.

[0076]However, the aforementioned arrangements of the envelopes are not limiting. In particular, each envelope and the functional component 71 can be provided with the desired properties, such as elasticity, waterproofness, wear resistance, fungicidal properties, the desired aesthetic appearance, or the like.

[0077]Still according to the first embodiment, the thickness of the first envelope 21 is less than or equal to 5.0 mm, considering that values of less than or equal to 3.0 mm have yielded good results. This lightens the first envelope 21.

[0078]Similarly, the thickness of the second envelope 31 is less than or equal to 5.0 mm, considering that values of less than or equal to 3.0 mm have yielded good results. This lightens the second envelope 31.

[0079]The thickness of the functional component 71 is less than or equal to 3.0 mm. This makes it lighter.

[0080]For each component 21, 31, 71, thickness is measured after melting of the yarns comprising at least one hot-melt filament.

[0081]Ultimately, the shoe 1 according to the invention is lighter than a shoe according to the prior art, with comparable technical specifications.

[0082]The other embodiments of the invention are briefly described below with reference to FIGS. 11 to 14. For reasons of convenience, mainly the differences from the first embodiment are identified. In addition, the same reference numerals are used for identical or similar elements seen in the first embodiments.

[0083]Thus, the second embodiment, according to FIGS. 11 and 12, features an article of footwear or shoe 1 with a rear end 4 and a front end 5, a lateral side 6 and a medial side 7, or a bottom 12 and a top end 13.

[0084]What is specific to the second embodiment is the structure of the preform or sleeve 41. The sleeve extends well between a first end 42, which is for example closed, and a second open end 43. However, the sleeve 41 is sized to obtain the first envelope 21 only, to the exclusion of any other envelope or envelope subdivision. Accordingly, it is the open end 43 of the first envelope 21 which alone demarcates the foot insertion opening 84. The shoe 1 according to the second embodiment therefore comprises the first envelope 21, the functional component 71, and the reinforcement 51, with its tightening device 61, to the exclusion of any additional envelope. It can also be said that the reinforcement 51 covers the first envelope 21. This means that the shoe 1 is further lighter than the shoe according to the first embodiment. Also provided is an outer sole assembly 78 for the shoe according to the second embodiment, although this is not essential.

[0085]For the third embodiment, according to FIGS. 13 and 14, there is a sleeve 41 sized to obtain the first envelope 21 only.

[0086]What is specific to the second embodiment is that it comprises a plurality of functional components. In this case, the functional component 111, towards the rear 24, is a rear stiffener. It is also a three-dimensional element. Towards the front, the functional component 121 is a front end piece. It is also a three-dimensional element. These elements 111, 121, for example, improve the resistance to abrasion, or provide greater rigidity. The three-dimensional shape facilitates placement and positioning.

[0087]The invention is not limited to the embodiments described above, and includes all technical equivalents that fall within the scope of the claims that follow.

[0088]In particular, one or more functional components 71, 111, 121 may be provided.

[0089]Each functional component is arranged either inside an envelope or outside of an envelope, or between two envelopes, depending upon the desired technical effects.

[0090]In certain cases, the positioner to position the functional component 71, 111, 121 with respect to the envelope 21, 31 comprises an adhesive product.

[0091]In other cases, the positioner to position the functional component with respect to the envelope comprises fastening elements.

[0092]The invention is applicable to any type of shoe having an upper made of a compatible material. In this case, the upper is mounted on a last, and then the functional component having predetermined characteristics is positioned on the upper and glued, before the outer sole assembly is finally added.

[0093]The invention relates to a method for manufacturing an article of footwear comprising a first envelope, the first envelope extending lengthwise from a rear end to a front end, widthwise between a lateral side and a medial side, and heightwise from a bottom to a top end, the method comprising a step of adding a functional component to the lasted envelope before assembly with an outer sole assembly.

[0094]In this manufacturing method according to the invention, the functional component is provided with a positioner, for example by using a tubular section/sock portion or other three-dimensional shape enabling easy positioning, and also by using extensible material, for example for the tubular section/sock portion.